1. Field of the Invention
The present invention relates to a light emitting device capable of switching an image direction vertically to horizontally and also relates to an electronic apparatus using the light emitting device.
2. Description of the Related Art
A portable electronic apparatus typified by a mobile phone, an electronic notebook and the like requires multiple functions such as sending and receiving e-mail, voice recognition, taking-in images by a small camera as well as a display device for displaying images. On the other hand, reduction in the size and weight of the portable electronic apparatus is still sought for satisfying the user needs. Therefore, as many ICs having larger circuit scale and memory capacity as possible are required to be mounted on the narrow space of the portable electronic apparatus. It is an essential part to make a flat panel display to be mounted as thin and light as possible in order to achieve the reduction in the size and weight of the portable electronic apparatus while making space for mounting ICs and realizing multiple functions.
For example, as for a liquid crystal display device which is used for a portable electronic apparatus in relatively many cases, a light source, an optical waveguide and the like are required when it is a transmissive display device, and thus reduction in the weight and thickness of the electronic apparatus is prevented. Meanwhile, in the case of a reflective liquid crystal display device utilizing outside light, an image is recognized with difficulty in the dark, resulting in abandonment of the advantage of a portable electronic apparatus that is capable of being used in all places. In view of the foregoing, a portable electronic apparatus including a light emitting device using a light emitting element as a display element has been recently developed and put into practical use. Since the light emitting element emits light by itself, an image can be clearly displayed even in the dark without a light source which is needed in the liquid crystal display device. Accordingly, the use of a back light typified by a light source and an optical waveguide can be omitted, leading to reduction in the thickness and weight of a display device.
As set forth above, the thicker and lighter a display device is, the easier it is to realize multiple functions of a portable electronic apparatus while reducing the size and weight. For example, disclosed is in Patent Document 1 below a structure of a display device which is capable of switching an image direction vertically to horizontally without a frame memory additionally provided.
Patent Document 1
Japanese Patent Laid-Open No. 2003-076315